


Infinite Diversity in Infinite Combinations

by malacophilous (orphan_account)



Category: Sherlock (TV), Star Trek
Genre: Alien Gender/Sexuality, Alien Sex, Alternate Universe - Fusion, Different species, First Time, M/M, Minor Injuries, Pon Farr, Vulcan
Language: English
Status: Completed
Published: 2011-05-24
Updated: 2011-05-24
Packaged: 2017-10-29 16:12:57
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,959
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/321741
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/malacophilous
Summary: <blockquote class="userstuff">
              <p>Sherlock is an alien--an alien with NEEDS.</p>
            </blockquote>





	Infinite Diversity in Infinite Combinations

**Author's Note:**

> This fills two prompts: Sherlock is an alien and anally probes John, and a shag-or-die scenario.

They had been arguing for an hour; John’s fists were sore from clenching them, and he was getting hoarse. It had all been pretty regular, the usual bones of contention between them, until John snapped, ‘Do you even  _have_  emotions?’   
  
And though John had asked this before, many times, Sherlock tensed, different shades of fear clicking across his expression like slides. ‘I do my best not to.’   
  
John snorted, disbelieving. ‘Don’t try to say you’re a sociopath, Sherlock. I’ve actually done  _my_  research.’   
  
Sherlock stared at his hands as if they were trying to tell him something. ‘It’s the easiest explanation for some people.’   
  
‘Since when do you care about easy explanations?’ John demanded, but Sherlock was getting up, leaving, descending the stairs. ‘Hey, come back!’   
  
But Sherlock was gone.   
  
  
‘We’re meant to help maintain the peace,’ Mycroft told him, ‘not draw attention to ourselves, and  _certainly_  not have screaming rows with the humans we’ve somewhat taken into our confidence! Have you forgotten your orders?’   
  
‘Of course not,’ Sherlock retorted, kicking at the pavement angrily. ‘He’s just so  _frustrating.’_   
  
Mycroft sighed as he looked away, up at the fog-shrouded stars. ‘You used to not care whether it was frustrating, brother. None of the rest of us do. Are their feelings rubbing off on you? Perhaps you need to take a—’   
  
‘No,’ Sherlock grumbled, spite written in every line of his posture, but he was lying.   
  
  
Sherlock was usually very careful about not needing medical attention, but of course he hadn’t planned on being knocked unconscious by a falling crate. When he came to, John was leaning over him, looking concerned.   
  
‘They’re gone,’ John told him, ‘they took the counterfeits with them. You okay?’ He was looking back and forth between Sherlock’s eyes, quickly, comparing pupil sizes, checking his pulse from one rope-abraded wrist.   
  
Sherlock pushed him off. ‘I’m fine, John. Which exit did they take?’   
  
‘You just got knocked senseless,’ John said sternly. ‘A hundred-pound box just landed on your chest! We’re not going anywhere just yet.’   
  
_‘Which exit?’_  Sherlock snarled, getting to his feet, swaying only a little.   
  
John sighed. ‘Out the back.’   
  
‘That wasn’t so hard, was it?’   
  
‘When we get home,’ John insisted, ‘you’re going to sit still long enough for me to check your vitals properly.’   
  
  
But Sherlock was only still when he was sleeping. Thus, John examined him then.   
  
The next morning, as Sherlock sat on the sofa and John made them tea, John said, ‘You could have told me you’ve got dextrocardia.’   
  
Sherlock tensed. ‘What?’   
  
John said from the kitchen, ‘Your heart’s on the right side of your body, Sherlock.’   
  
‘I know.’   
  
‘Well, you could have said something! What if there was an emergency,’ John paused, correcting himself, ‘a more  _serious_  emergency, and the paramedics didn’t know?’   
  
‘It’s never happened before,’ Sherlock noted, ‘and I plan for things to stay that way.’   
  
  
Mrs Hudson had brought them Nutella biscuits.   
  
As John munched on one he asked Sherlock, ‘Do you want some? They’re quite good.’   
  
Sherlock didn’t look up from his computer. ‘I don’t eat chocolate.’   
  
John stared at him. ‘I’m sorry. Allergic?’   
  
‘There are negative effects, yes,’ Sherlock answered brusquely.   
  
  
The cut was minor, and Sherlock seemed perfectly calm about it, but John wasn’t.   
  
‘First dextrocardia,’ John snapped at him, ‘and now you’ve got sulfhemoglobinaemia, as well?’   
  
‘I have migraines,’ Sherlock lied smoothly. ‘That particular colour can be caused by taking Sumatriptan.’   
  
John passed a wrist over his eyes. ‘God, Sherlock, what all do I not know about you?’   
  
Sherlock dabbed at the green blood on his hand with a scrap of kitchen roll. ‘Most things.’   
  
  
They had been sitting in silence, both working on their respective online projects, when John spoke up.   
  
‘Question for you.’   
  
Sherlock didn’t look at him. ‘Hmm?’   
  
‘During the Study in Pink case,’ John said, sounding somewhat hesitant, ‘when we first went into the room where the body was, you held out your hand for a moment.’ John copied the motion. ‘Like this. Do you remember?’   
  
Sherlock frowned at his screen. ‘Yes, why?’   
  
‘I haven’t seen you do it since, but it’s stuck in my brain for some reason.’ John laughed, shaking his head. ‘It’s stupid, I know, but I wondered. It’s not like you’re telepathic or something, right?’   
  
Sherlock smiled a little. ‘Of course not, John, that’s ridiculous.’   
  
  
John stared down at Moriarty, who was sprawled at their feet, before looking up at Sherlock with wide eyes. ‘God, Sherlock, what the hell did you do to him?’   
  
‘Applied adequate pressure to the Subclavian nerve to render him unconscious,’ Sherlock said dismissively. ‘Phone Lestrade, would you? I feel the need to wash my hands.’   
  
  
Sherlock’s phone flashed on in the dark. He picked it up, answering the call.   
  
‘The hour approaches,’ said Mycroft, without so much as a greeting. ‘Are you prepared?’   
  
A sigh. ‘I’m locking myself in my room and waiting it out.’   
  
‘Don’t be an idiot, you could go mad! The strain could  _kill_  you!’   
  
Sherlock realised he was shaking already, and focused his every energy on calming himself, forcing down what he knew to be inevitable. ‘There are worse things than madness and death, Mycroft.’   
  
And he ended the call. A few moments later, feeling regretful, Sherlock sent his brother a text:   
  
_LLAP \\\//_   
  
  
Sherlock lasted five hours—trembling, frightened, his brow dappled with sweat, attempting to meditate though he knew it was useless—before he couldn’t stand it anymore. He left his room in his pyjamas, t-shirt clinging wetly to his shivering back.   
  
John was watching telly in the sitting room, and only looked up when Sherlock took the remote from the armrest and switched off the machine. ‘What’s wrong, are you ill?’   
  
‘Yes,’ Sherlock replied, his voice shaking. ‘I need your help.’   
  
John, who was used to thoughtless demands on his time rather than direct requests for aid, knew that it had to be serious. ‘What can I do? Do you need to go to hospital?’   
  
‘No,’ Sherlock said weakly, and John could see even in the dim light from the kitchen that his eyes were dilated, only faint rings of blue around the black, and his face was oddly flushed. ‘There’s nothing they could do.’   
  
John didn’t know if this was Sherlock’s usual bloody-mindedness and melodrama at work, but he had a feeling that Sherlock was being honest. ‘How can I help, then?’ he asked, getting to his feet.   
  
But instantly he was back in the chair again, Sherlock straddling his legs, holding him down, kissing him with a hopeless desperation that, against his better judgement and long-held opinions of himself, John found fantastically arousing. He reached up to run his fingers through Sherlock’s hair, lost in the moment, until his hands brushed something that ought not to have been there.   
  
He pulled back, staring even as Sherlock tried to lean in again, parting the hair that covered the tops of Sherlock’s ears. ‘What is this?’ John asked wonderingly. ‘What  _are_  you?’   
  
‘Forgot to switch on the hologram before coming in,’ Sherlock said breathlessly, kissing along John’s jaw line.   
  
‘ _Hologram?_  What are you saying?’   
  
Sherlock made an irritated noise. ‘Shut up, John, I’ll explain later, but right now I have to fuck you, or I  _will_  die.’   
  
As Sherlock scrabbled at the buttons of John’s shirt and then at the buckle of his belt, John gaped at him. ‘You’re serious. You’re actually serious, aren’t you?’   
  
‘Please,’ Sherlock whimpered. He’d managed to unfasten John’s trousers despite the frenetic tremors in his hands, John’s rapidly stiffening cock already in his grasp. ‘Please, John, I  _need_  this.’   
  
John was at a loss, trying to focus. ‘I’ve never done this.’   
  
Sherlock was currently mouthing against his neck, but found time to be snide. ‘ _Obviously,_  as Mycroft’s the only other person you know with this specific biological imperative.’   
  
John, despite his confusion, almost laughed. ‘No, I mean...’   
  
‘Ah,’ Sherlock said as he nipped at John’s earlobe, ‘you mean sex with another man.’   
  
John squirmed, approaching the realisation that perhaps he ought to have done, before now, because Sherlock’s kisses were _devouring_ , and Sherlock’s hand, large and long-fingered around John’s cock, was somehow better than any woman’s touch had been in John’s rather extensive experience.   
  
‘It’s not difficult,’ Sherlock went on, though he sounded as if he were forcing his sounds to string together into words, ‘I know what I’m doing.’   
  
Soon they were (mostly) undressed, on the floor, and somehow Sherlock had ended up under John.   
  
‘Thought you were topping,’ said John, trying not to think of how strange it was to be stroking Sherlock’s cock, which was flushed a pretty (and entirely unsettling) green, slightly narrower and more tapered than others John had seen, the skin dappled in a random pattern of almost-blue.   
  
‘I am,’ Sherlock replied.    
  
‘Why,’ said John, suddenly realising what was missing, ‘haven’t you got bollocks?’   
  
‘They’re internal,’ Sherlock told him as if it were obvious, reaching over to the desk, opening the bottom drawer and grabbing a small bottle of lubricant.   
  
‘Why’s there lube in the desk?’   
  
Sherlock, despite his trembling and feverishness, smirked. ‘Experiments. Are you comfortable with me inserting my fingers—?’   
  
‘No,’ said John, then, ‘yes.’ Half a breath. ‘Not really. I don’t know.’   
  
Sherlock handed him the bottle, eyes wide and fathomlessly black. ‘Then do it yourself.’   
  
John was straddling him, one knee on either side of Sherlock’s legs, and as he angled his hand behind his own back it was the most awkward moment he felt had ever transpired between them, including the time when Sherlock had asked him, in all seriousness, why people on telly could talk frankly about each other’s infidelity when in real life it was considered the height of rudeness.   
  
‘Be careful,’ Sherlock advised, though the look on his face was far more hungry than cautious.   
  
For several minutes it was terrifically uncomfortable, Sherlock panting beneath him, John grimacing and getting used to the feeling of his own fingers inside himself, but the slight pain faded quickly to be replaced with a sort of simmering eagerness, a pleasant blur of want at the edges of John’s mind. He knew how it worked, of course—nerve endings, the prostate and all that—but he was nonetheless surprised when he started to like it.   
  
Once John had slowly, gradually worked up to three fingers, Sherlock glared at him. ‘Are you quite finished, or should I leave you alone with your hand? It’s only that any moment now I may start quite literally  _losing my mind.’_   
  
John removed his fingers, sighing at the sudden emptiness, feeling bereft but excited for something more, something bigger, something of Sherlock’s. ‘All right, fine, calm down.’   
  
‘Sorry,’ Sherlock told him, looking uncharacteristically annoyed with himself. ‘I have these outbursts of unchecked emotion, I can’t... it’s difficult to control.’   
  
John shook his head, smiling. ‘People have that, Sherlock, it’s called being alive.’   
  
Sherlock had at some point in the proceedings grabbed a condom out of the desk drawer, put it on and slicked several ounces of extra lube over it, far more than seemed entirely necessary but John felt it was probably a good thing. ‘Rise up a little more on your knees, and tilt your pelvic floor at a 22.5 degree angle to where it is now.’   
  
‘God, Sherlock,’ John laughed despite himself, ‘I haven’t got a protractor handy.’   
  
John almost expected him to take one out of the drawer, but Sherlock huffed impatiently and tilted John’s hips himself, broad hands circling John’s sides, lowering him gently onto his cock.   
  
Sparks shot behind John’s eyes as he adjusted to the depth and fullness, and though he didn’t remember deciding to do it, he whimpered, squeezing his eyes shut and biting his lip.   
  
‘Good,’ said Sherlock, and even with his cock sheathed in John to the hilt he was able to sound clinical and detached, ‘my thoughts are already clearer. Can you roll your hips, or would moving up and down work better for you?’   
  
‘You’re being  _considerate,’_  John said wonderingly, though his voice was small and hitched as he rose up on his knees again, the sensation almost overwhelming.   
  
Sherlock dismissed the notion with a gesture. ‘I’m feverish.’   
  
‘Maybe you should be feverish more often.’   
  
Sherlock actually laughed. ‘Once every seven years.’   
  
John continued to rock against him, groaning, picking up the tempo as he adjusted to the feeling, found the right angle so that Sherlock’s cock bumped against his prostate with every stroke. Sherlock looked impassively up at him, his hands still on John’s hips.   
  
John frowned at him, though his words were interrupted with pleasure. ‘Are you— _fuck_ , right there!—are you enjoying this at all?’   
  
‘Excessively so,’ Sherlock replied, his eyes falling closed for a moment before snapping open again. ‘I hide it well.’   
  
‘Don’t,’ said John, arching his spine, leaning back, supporting himself on one hand outstretched behind him on the floor beside Sherlock’s knee. ‘Please don’t.’   
  
‘It’s not a switch, John, I can’t just turn it on and off.’   
  
John used his free hand to dash a long, sharp scratch down Sherlock’s chest, and Sherlock hissed through his teeth, writhing beneath him, for the first time showing that he was actually involved in the situation.   
  
John leaned over him, going back to his previous position, smirking as he pinched one of Sherlock’s dark, faintly-emerald nipples. _‘Try.’_   
  
Sherlock bit his lower lip, his expression conflicted. ‘If I do, it may never switch back off again.’   
  
John bucked hard, and Sherlock gasped, eyes flickering back in his head. ‘I don’t care, maybe I’d like you better.’   
  
‘I’d be a holy terror.’   
  
John snorted with laughter. ‘You already are.’ He leaned down farther, kissing Sherlock briefly, and as the angle changed he moaned. ‘ _God_ , that’s perfect—I’m getting close, are you?’   
  
Sherlock nodded, accidentally bumping his head against the floor. ‘I can feel the fever breaking.’   
  
‘That’s not what I meant,’ John said, clenching around Sherlock, wanting a reaction.   
  
Sherlock gave him one: a low, coarse growl in the back of his throat. When he spoke again, his voice was rough-edged and disarmingly needy. ‘It’s the same thing, John.’   
  
‘No, it isn’t.’   
  
‘Stop arguing with me,’ Sherlock sighed, ‘and keep doing precisely what you’re doing.’   
  
John did, and soon the room was filled with their cries as they came, Sherlock first, his fingers digging into John’s sides, and John shortly after, the majority of his come landing across Sherlock’s face and neck, a little on one pointed ear.   
  
John held still for a long moment before deciding it would be best to climb off; his knees were sore and carpet-burned, and he had a crick in his back. Rising up on his aching knees, he slid Sherlock’s cock out of him and flopped unceremoniously down onto the floor beside him.   
  
‘Well,’ John said, breathing hard, rolling the condom off of Sherlock and staring at its slightly blue-tinged contents, ‘that was... amazing. How’s your brain? Everything okay?’   
  
Sherlock was squinting, rubbing at his face. ‘Perfectly normal.’   
  
A snort of amusement. ‘I doubt that.’   
  
‘You got ejaculate in my eye.’   
  
John shrugged. ‘That’s what you get for being in the line of fire.’   
  
And Sherlock looked over at him, one eye screwed closed, a comically pained expression on his face, and they started laughing, both of them at last seeing the ridiculousness of the situation.   
  
‘I just fucked an alien,’ John said through his laughter.   
  
‘ _Got_  fucked,’ Sherlock snorted, eyes watering from mirth and other foreign substances.   
  
‘I was doing the work!’   
  
‘Doesn’t matter.’   
  
‘It absolutely does.’   
  
‘Shut up.’ And Sherlock was sitting up, kissing him, and his face was sticky and clammy with cold fever-sweat but neither of them particularly cared.   
  
When they broke apart, John said, ‘Every seven years, huh?’   
  
Sherlock nodded, damp curls clinging to his forehead. ‘ _Pon farr_  is every seven, yes, though of course I can have sex at other times—’   
  
‘And we will be,’ John added, determination in his voice. ‘Having more sex, I mean. Because that was fantastic.’   
  
Sherlock looked surprised, wearing the same expression as when John complimented him on his deductive reasoning. ‘Was it really?’   
  
John gave him a look. ‘Yes, Sherlock, actually, it was. What’s  _pon farr_ ?’   
  
‘During  _pon farr_ , if I don’t engage in intercourse with my mate, the results are... morbidly unpleasant.’   
  
‘Wait,’ John frowned at him, ‘I’m not... not pregnant with alien babies, am I?’   
  
Sherlock fell back, cackling with laughter again.   
  
‘I’m serious!’ John said, but he was snickering. ‘Nothing’s going to burst out of my chest or something, right?’ He prodded Sherlock in the side with his foot. ‘Right?’   
  
‘We used a condom, you’ll be fine,’ Sherlock said, grabbing his fallen shirt to finally wipe off his face. ‘And besides, I had the equivalent to German measles as a child; I’m sterile.’   
  
‘Oh, thank God,’ John sighed, leaning back against the side of one of the armchairs. He noised thoughtfully. ‘Did you just say I was your  _mate_ ?’   
  
Sherlock was facing away, putting the lube back in the desk drawer, when he answered. ‘You’re the only human I trust.’   
  
John felt a flutter of happiness ricochet around beneath his ribs. ‘Oh.’   
  
‘If you’d prefer, in the future I could ask Mycroft to—’   
  
‘No,’ John interrupted him, ‘no, it’s fine. I’m okay with this.’ He made a face. ‘Also, that is spectacularly gross.’   
  
Sherlock turned back to him, rolling his eyes. ‘I meant I’d ask him to arrange for me to partake of the ritual with one of the other Vulcan delegates.’   
  
‘Is that what you’re called, Vulcan?’   
  
Sherlock nodded. ‘That’s my planet, as well.’   
  
‘I see.’ John glanced at the telescope by the window. ‘Can you see it from Earth?’   
  
Sherlock’s smile was almost wistful. ‘On clear nights.’   
  
John found he was smiling, too. ‘Show me?’


End file.
